arm: meson: implement calls to secure monitor
Implement calls to secure monitor to read the MAC address from e-fuse.
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
diff --git a/arch/arm/mach-meson/sm.c b/arch/arm/mach-meson/sm.c
new file mode 100644
index 0000000..1b35a22
--- /dev/null
+++ b/arch/arm/mach-meson/sm.c
@@ -0,0 +1,57 @@
+/*
+ * (C) Copyright 2016 Beniamino Galvani <b.galvani@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * Secure monitor calls.
+ */
+
+#include <common.h>
+#include <asm/arch/gxbb.h>
+#include <linux/kernel.h>
+
+#define FN_GET_SHARE_MEM_INPUT_BASE 0x82000020
+#define FN_GET_SHARE_MEM_OUTPUT_BASE 0x82000021
+#define FN_EFUSE_READ 0x82000030
+#define FN_EFUSE_WRITE 0x82000031
+
+static void *shmem_input;
+static void *shmem_output;
+
+static void meson_init_shmem(void)
+{
+ struct pt_regs regs;
+
+ if (shmem_input && shmem_output)
+ return;
+
+ regs.regs[0] = FN_GET_SHARE_MEM_INPUT_BASE;
+ smc_call(®s);
+ shmem_input = (void *)regs.regs[0];
+
+ regs.regs[0] = FN_GET_SHARE_MEM_OUTPUT_BASE;
+ smc_call(®s);
+ shmem_output = (void *)regs.regs[0];
+
+ debug("Secure Monitor shmem: 0x%p 0x%p\n", shmem_input, shmem_output);
+}
+
+ssize_t meson_sm_read_efuse(uintptr_t offset, void *buffer, size_t size)
+{
+ struct pt_regs regs;
+
+ meson_init_shmem();
+
+ regs.regs[0] = FN_EFUSE_READ;
+ regs.regs[1] = offset;
+ regs.regs[2] = size;
+
+ smc_call(®s);
+
+ if (regs.regs[0] == 0)
+ return -1;
+
+ memcpy(buffer, shmem_output, min(size, regs.regs[0]));
+
+ return regs.regs[0];
+}